Troponin-I: predictor of early postoperative outcome after repair of Tetralogy of Fallot

The tetralogy of Fallot is the most common cyanotic congenital cardiac disease with a prevalence of 3-6 per 10’000 live births (1,2). Its main features are: right ventricular outflow tract obstruction (RVOTO), ventricular septal defect (VSD), deviation of the origin of the aorta to the right, and right ventricular hypertrophy (3). This disease is lethal in the early infancy particularly and a surgical correction is thus necessary (4). Since this surgery is associated with early complications, such as an important need of ventilation, a long stay in the pediatric intensive care unit (PICU) or even death, it would be beneficial to research a plasmatic marker that could help predict the early post-operative prognostic. Troponin-I is an an important and unique component of the cytoskeleton of the myocardial cells. For this reason its plasmatic level is used to determine the myocardial damage in myocardial ischemia. Surgical repair of the Tetralogy of Fallot is associated with a resection of the infundibulum depending on the severity of the RVOTO and with a closure of the VSD. Troponin-I is then released in the systemic circulation and continues to do so according to the severity of the locally induced ischemia. We can then imagine that the Troponin-I variables reflect not only the postoperative outcome directly caused by the operation but also the severity of the postoperative myocardial injury. Studies have shown that the pre- and postoperative Troponin-I is a good predictor of mortality in overall cardiac surgical repair, especially for its stability against impaired renal function and its myocardial specificity (5–8). This study will analyze a possible correlation between specific Troponin-I values (such as plasmatic peaks, area under the curve and others) and the early postoperative outcome of young patients operated for a Tetralogy of Fallot.